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针对核设施退役过程中可能存在对设施内部放射性预估不当而导致在解体去污过程中辐射量超标的紧急情况,采用实验室一步成型法制备了一种可快速固化的阻燃聚氨酯复合屏蔽材料,研究了屏蔽填料(氧化钨)及阻燃填料(硼酸锌)的总含量对材料固化时间、微观结构、密度、压缩强度、阻燃性能及屏蔽性能的影响。结果表明,双组分聚氨酯混合体系的乳白时间受填料含量变化的影响较小,而表干时间随填料含量增大先减小后增大,但仍保持较快的固化速度;填料主要分布在泡孔孔壁中,随着填料含量的增加,材料的泡孔逐渐细化;材料的密度随填料含量增加逐渐变大而压缩强度逐渐减小;极限氧指数随着硼酸锌含量增加逐渐提高;不同γ射线能量下射线的透射率随填料含量增加逐渐减小,但是随着射线能量增强材料屏蔽性能逐渐减弱,在相同能量下,增加材料的厚度可以有效改善其屏蔽性能。当氧化钨和硼酸锌质量分数分别为40%和20%时,该新型复合屏蔽材料具有较短的固化时间和较好的阻燃及力学性能,在中低能射线辐照下具有较好的屏蔽性能,其在应对核电站退役过程中保障工作人员辐照安全方面具有较大的应用前景。
In the light of the emergency situation that the radiation of the facilities in the decommissioning decontamination process may be caused by improper estimation of the radioactivity inside the facilities during the decommissioning of the nuclear facilities, a rapid solidified flame-retardant polyurethane composite shielding material is prepared by a laboratory one-step molding method , The effects of the total content of shielding filler (tungsten oxide) and flame retardant filler (zinc borate) on the curing time, microstructure, density, compressive strength, flame retardancy and shielding properties were studied. The results showed that the milky time of the two-component polyurethane mixed system was less affected by the change of filler content, while the surface dry time first decreased and then increased with the increase of filler content, but still maintained a fast curing speed. Fillers were mainly distributed in With the increase of the content of filler, the cell density of the material gradually refined. The density of the material gradually increased with the increase of filler content and the compressive strength decreased gradually. The limiting oxygen index increased gradually with the increase of zinc borate content. The transmittance of the rays under the beam energy decreases with the increase of the filler content. However, with the increase of the shielding energy of the beam, the shielding properties of the material decrease with the increase of the material thickness. When the mass fraction of tungsten oxide and zinc borate is 40% and 20%, respectively, the new composite shielding material has a shorter curing time and better flame retardance and mechanical properties, and has better shielding under low and medium energy radiation Performance, which has great application prospects in the protection of staff radiation safety in the process of decommissioning nuclear power plant.